Hi guys,
I am trying to figure what is the problem with my combo DVD/VCR, when I first bought it it was acting wonderfully, but one day those annoying horizontal noise start to appear
https://www.youtube.com/shorts/naRgArjaEPQ It does the same thing on composite, s-video, component and even HDMI. Yes, it is one of the rare VHS player that can player through HDMI.
I have located the service manual, but it is pretty much useless there is no schematic, only how to disassemble the player, spare parts and some diagnostic tools. I have tried to measure the ESR on the caps on the board, everything is all good within range. I initially thought that It was perhaps a ground loop issue or a filter cap issue. I have tried to ground near the connector directly on the chassis and no improvement. I have spent several hours trying to figure what might be the issue. The only problem that I have figured out is there is something strong that "open" the diode as they let go of the current of both side, but they test fine when pull out of circuit.
Anyone has a clue? So far this thing has been a nightmare to diagnostic.